[RFC v1 0/2] RCU dyntick nesting counter cleanups

From: Joel Fernandes (Google)
Date: Mon Aug 26 2019 - 21:34:15 EST


These patches clean up the usage of dynticks nesting counters simplifying the
code, while preserving the usecases.

It is a much needed simplification, makes the code less confusing, and prevents
future bugs such as those that arise from forgetting that the
dynticks_nmi_nesting counter is not a simple counter and can be "crowbarred" in
common situations.

Several nights of rcutorture testing with CONFIG_RCU_EQS_DEBUG on all RCU
kernel configurations have survived without any splats.

Further testing is in progress, hence marked as RFC!

thanks,

- Joel

Joel Fernandes (Google) (2):
rcu/tree: Clean up dynticks counter usage
rcu/tree: Remove dynticks_nmi_nesting counter

.../Data-Structures/Data-Structures.rst | 31 ++----
Documentation/RCU/stallwarn.txt | 6 +-
kernel/rcu/rcu.h | 4 -
kernel/rcu/tree.c | 98 +++++++++----------
kernel/rcu/tree.h | 4 +-
kernel/rcu/tree_stall.h | 4 +-
6 files changed, 64 insertions(+), 83 deletions(-)

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2.23.0.187.g17f5b7556c-goog